Collapsing arithmetic expansion is incorrect when the inner arithmetic
expansion is a part of a parameter expansion.
Test case:
unset a
echo $((3 + ${a:=$((4 + 5))}))
echo $a
Old result:
12
(4 + 5)
New result:
12
9
Based on commit bb777a6 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu
function old new delta
readtoken1 3180 3163 -17
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>